Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
  • A61B3/02—Subjective types, i.e. testing apparatus requiring the active assistance of the patient
  • A61B3/028—Subjective types, i.e. testing apparatus requiring the active assistance of the patient for testing visual acuity; for determination of refraction, e.g. phoropters
  • A61B3/032—Devices for presenting test symbols or characters, e.g. test chart projectors
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
  • A61B3/0008—Apparatus for testing the eyes; Instruments for examining the eyes provided with illuminating means
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
  • A61B3/0016—Operational features thereof
  • A61B3/0025—Operational features thereof characterised by electronic signal processing, e.g. eye models
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61B—DIAGNOSIS; SURGERY; IDENTIFICATION
  • A61B3/00—Apparatus for testing the eyes; Instruments for examining the eyes
  • A61B3/0016—Operational features thereof
  • A61B3/0041—Operational features thereof characterised by display arrangements

Definitions

• luminance standards have not heretofore been adopted by practicing eye doctors primarily because most eye doctors used the same type of vision testing equipment, which inherently created less variance due to the similarities of the devices.
• the required accuracy of vision testing was not such that differences in luminance levels between examination lanes or between eye clinics would create a problem for documenting the visual performance.
• the present invention includes a vision testing system and a method of operating a data processing system for displaying an eye test pattern on a computer display to a patient during an eye examination.
• the method includes causing the data processing system to display the eye test pattern in a chart region of a computer display controlled by the data processing system and characterized by a luminance in regions not displaying the eye test pattern.
• An intensity of light leaving the computer display is measured in a sensor region outside the chart region using a display luminance sensor.
• the luminance of the computer display is adjusted to provide a light level within a predetermined range of light levels based on the measured intensity of light.
• adjusting the luminance includes receiving the measured intensity by the data processing system and automatically adjusting the computer display in response to the measured intensity.
• the light intensity is measured by a sensor that views a portion of the computer display and wherein the sensor communicates directly with a user of the data processing system with instructions on changing the luminance of the computer display.
• the method includes providing an ambient light sensor proximal to the patient's eyes that measures a light intensity in a room containing the patient and causing the data processing system to alter the ambient light intensity in the room such that the light intensity in the room is within predetermined limits.
• the ambient light sensor is positioned such that light from the computer display is not directly received by the ambient light sensor.
• the method includes measuring the luminance of the display in the chart region, and measuring the luminance in the sensor region, the data processing system calibrating the measured luminance in the sensor region to the measured luminance in the chart region.
• the display luminance sensor is used to measure the luminance in both the chart region and the sensor region.
• the method includes providing a glare light source proximately located to the chart region, the glare light source is characterized by a glare luminescence, measuring the glare luminescence with the light luminance sensor, and causing the data processing system to adjust the glare light source intensity such that the measured glare luminescence is within a predetermined range.
• a vision testing system includes a data processing system, a luminance sensor, and a display intensity adjustment system.
• the data processing system includes a computer display, characterized by a display luminance, on which the data processing system displays an eye test pattern in a chart region of the computer display.
• the luminance sensor is positioned to measure a light intensity in a sensor region of the computer display, the sensor region being outside of the chart region.
• the display intensity adjustment system receives an output from the luminance sensor and causes the computer display to change the display luminance such that the output from the luminance sensor is within predetermined limits.
• the display intensity adjustment system is separate from the data processing system.
• the display intensity adjustment system includes a program running on the data processing system which automatically adjusts the display luminance in response to the measured light intensity in the sensor region.
• the display intensity adjustment system includes an interface that instructs a user of the system to manually change the display luminance.
• the luminance sensor reversibly attaches to the computer display.
• the luminance sensor is powered by light received from the computer display.
• the system includes an ambient light sensor positioned proximate to a patient's head to measure ambient light at a location of a patient's eyes and to communicate the measured ambient light to the data processing system.
• the data processing system causes the ambient light to be changed such that the measured ambient light is within predetermined limits.
• the system includes a glare source that includes a light source in close proximity to the chart region, the glare source emitting light characterized by a glare luminescence, wherein the illumination sensor measures the glare luminescence and the data processing system adjusts the glare luminescence such that the glare luminescence is within a predetermined range.
• Figure 1 illustrates a display according to one aspect of the present invention.
• Figure 2 illustrates one embodiment of an luminescence sensor that can be utilized in the present invention.
• Figure 3 illustrates one embodiment of a self-powered sensor according to the present invention.
• Figure 4 is a top view of an examining room in which a patient is undergoing an eye examination.
• Figure 5 illustrates a testing system that utilizes a glare source.
• the present invention is based on the observation that computer displays not only deviate from display to display in luminance, but are also subject to changes when the display is used for other tasks, as the operator can adjust the display brightness to suit his or her needs. Hence, a mechanism that adjusts the luminance to the desired range at the start of the eye examination is required to guarantee that the examination is performed under standardized conditions.
• Display 20 is connected to a controller, which is typically a conventional data processing system 22.
• the controller causes display 20 to display a conventional eye chart in a chart display area 23.
• a removable sensor 21 is positioned on display 20 in an area that is not used for the eye chart.
• Sensor 21 measures the average intensity of the light leaving display 20 and communicates that measurement to data processing system 22.
• Data processing system 22 then adjusts the intensity of display 20 such that the measured light intensity is within a predetermined intensity range.
• sensor 21 is connected to data processing system 22 by a conventional USB port. In this embodiment sensor 21 is powered by data processing system 22.
• sensor 21 is self-powered and communicates with data processing system 22 via a wireless communication link.
• sensor 21 can include a server that can be accessed via a conventional browser to view the measured light levels and lead the user through any calibration procedure.
• sensor 21 can be moved to different locations on display 20 to measure the intensity of light leaving the display at various locations.
• Computer displays are known to exhibit intensity variations across the display screens. These variations can be monitor specific. Hence, using the average luminescence over a limited area of the screen, particularly at one corner, as a proxy for the luminescence in the chart display area can be misleading. Hence, it is advantageous to measure the intensity at various locations in the chart display area and determine the relationship between the average luminescence in the chart display area and the luminescence at the sensor location.
• data processing system 22 or sensor 21 includes software for mapping the luminescence of display 20 in the chart display region and at the location at which sensor 21 normally resides.
• Embodiments in which multiple sensors measure the luminescent profile of the display can also be constructed.
• optional sensors 26 shown in Figure 1 can be placed at other locations on the display to measure the variations in screen intensity across the screen. These sensors also communicate with data processing system 22; however, to simplify the drawing, the connections between sensors 26 and data processing system 22 have been omitted.
• Figure 2 illustrates one embodiment of a luminescence sensor that can be utilized in the present invention.
• Sensor 30 includes a photodiode 31 that receives light from a region on display 20.
• An optional lens 34 collects light from the display over an area that is greater than the area of photodiode 31.
• the area of light that is routed to photodiode 31 must be sufficient to average any pixel to pixel variations in display 20.
• the current from photodiode 31 is proportional to the luminescence of the monitored area.
• the current is converted to a voltage by current- to- voltage converter 32.
• the output of current-to- voltage converter 32 is digitized by analog-to-digital converter (ADC) 33 and forms the output that is used by the processing programs or other circuitry to adjust the display luminescence or provide feedback to the user on how to adjust the display luminescence.
• ADC analog-to-digital converter
• the senor In embodiments of the present invention that are not connected to the data processing system by a wired connection that also supplies power to the sensor, the sensor must be self-powered. It is advantageous to avoid schemes in which the sensor is battery powered by a battery that must be replaced periodically.
• the photodiode is also used to power the sensor in embodiments in which the sensor is not connected to the data processing system by a wired link.
• Figure 3 illustrates one embodiment of a self-powered sensor according to the present invention.
• Sensor 40 taps the output of current-to- voltage converter 32 to run a power supply 35 which optionally charges a rechargeable battery 36. The output of power supply 35 is used to power the electronics in sensor 40.
• the connections between power supply 35 and the other components of sensor 40 have been omitted from the drawing.
• the amount of power that is available from photodiode 31 depends on the area of the display screen viewed by photodiode 31 and the intensity of light leaving that area. If the instantaneous power available from photodiode 31 is insufficient to power sensor 40, rechargeable battery 36 provides a mechanism for accumulating and storing the power output from photodiode 31 over time. In this regard, it should be noted that the amount of time that display 20 is dedicated to performing eye examinations is relatively small in most clinical settings.
• switch 38 is opened to remove power from the ADC 33 and wireless communication link 39. Since wireless communication link 39 requires significant power when it is on, powering down these components saves power while allowing rechargeable battery 36 to be charged from the output of photodiode 31.
• the user signals sensor controller 37 to close switch 38.
• sensor 40 is configured to operate in communication with the data processing system that controls the display and provides the chart for viewing by the patient such that the data processing system adjusts the luminescence of display 20 directly.
• sensor 40 provides a standalone configuration can also be constructed.
• sensor controller 37 communicates with the user directly to adjust the luminescence of display 20.
• sensor controller 37 includes a plurality of LEDs 41 that are viewable by the user who adjusts the luminescence of display 20 manually until sensor controller 37 indicates that the luminescence is in the desired range. To aid in the adjustment, one of the LEDs can be used to signal that the luminescence is too high, one to signal that the luminescence is too low, and one to signal that the luminescence is within the desired range. In such an embodiment, wireless communication link 39 is optional.
• sensor controller 37 can include a web server that can be accessed from any browser.
• the browser can be run on data processing system 22 or on a separate computer that communicates with sensor 40 via wireless communication link 39.
• the server can display the locations on display 20 at which the sensor is to be moved.
• the sensor can measure the luminescence in the chart display area and compare that to the luminescence in the location in which the sensor resides during normal operation. The measurements can be made for a number of different display luminescence values to provide a calibration curve for translating the measured luminescence to the luminescence in the display area.
• a number of considerations dictate the form factor of a sensor according to the present invention. The form of the sensor must allow the sensor to detect the display
• the sensor must not interfere with the patient's view of the chart area.
• the sensor must be able to attach to a conventional computer display.
• the attachment mechanism must be reversible. A clip that positions the sensor on the edge of the monitor can be used in such moveable embodiments.
• the sensor assembly can be attached to the monitor by an adhesive.
• FIG. 4 is a top view of an examining room in which a patient is undergoing an eye examination.
• Patient 52 views display 20 in the manner discussed above.
• a second luminescence sensor 51 is placed near the patient at approximately the same height as the patient's eyes. In one exemplary embodiment, the second luminescence sensor is placed within 6 inches of the patient's eyes.
• Luminescence sensor 51 communicates with data processing system 53 to provide a measurement of the luminescence at the patient.
• Data processing system 53 compares the luminescence measured by luminescence sensor 51 with the allowable range of ambient light levels.
• data processing system 53 can signal the technician to alter the ambient light in the room by displaying an appropriate message on display 20. In embodiments in which the ambient light in the examining room is under computer control, data processing system 53 can adjust the ambient light to the correct level.
• the present invention can also be utilized in other tests that present a test pattern of some sort on a monitor to the patient. Tests of peripheral vision, contrast sensitivity and depth perception are examples of such tests.
• the present invention can also be utilized to maintain a predetermined color temperature of the area of the screen displaying the eye test pattern.
• the sensor would include a plurality of sensors having different sensitivities in different wavelength bands. For example, sensors that measure intensity in the red, green and blue color bands can be used to measure color temperature and to servo the display to maintain a predetermined color temperature in addition to a predetermined intensity.
• each of the illumination levels is set by the processor using feedback from the sensor on the monitor.
• the present invention can also be utilized to provide standardization of illumination in testing systems in which a second "glare" source is also utilized. Such arrangements are utilized in tests for cataracts.
• Figure 5 illustrates a testing system that utilizes such a glare source.
• the testing system in Figure 5 is similar to that shown in Figure 1 ; however, in the embodiment shown in Figure 5, the glare sources 71 are placed on the edge of the monitor. However, embodiments in which the glare sources are on the screen near the test chart can also be constructed.
• the illumination monitor in which the illumination monitor is moveable, the monitor can be placed on each glare source during a calibration procedure in which the processor adjusts the signal to the glare source to arrive at a predetermined standard glare source level.
• the processor that controls the illumination levels in the above-described embodiments could be the same processor that provides the eye chart or other test patterns. Alternatively, a separate processor that only controls the screen illumination or glare source levels could be utilized.

Landscapes

• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Engineering & Computer Science (AREA)
• Medical Informatics (AREA)
• Surgery (AREA)
• Biophysics (AREA)
• Biomedical Technology (AREA)
• Heart & Thoracic Surgery (AREA)
• Physics & Mathematics (AREA)
• Molecular Biology (AREA)
• Ophthalmology & Optometry (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Signal Processing (AREA)
• Controls And Circuits For Display Device (AREA)
• Eye Examination Apparatus (AREA)
• Circuit Arrangement For Electric Light Sources In General (AREA)

Applications Claiming Priority (2)

Publications (2)

Family

ID=61688098

Family Applications (1)

Country Status (6)

Families Citing this family (4)

Family Cites Families (21)

• 2016
  • 2016-09-27 US US15/277,849 patent/US10016128B2/en active Active
• 2017
  • 2017-09-26 CN CN201780067276.3A patent/CN109922708B/zh active Active
  • 2017-09-26 WO PCT/US2017/053473 patent/WO2018064052A2/en unknown
  • 2017-09-26 EP EP17857286.3A patent/EP3518732A4/de not_active Withdrawn
  • 2017-09-26 KR KR1020197011151A patent/KR102422480B1/ko active IP Right Grant
  • 2017-09-26 JP JP2019538092A patent/JP7039602B2/ja active Active

Also Published As

Similar Documents

Legal Events